Open a terminal~\footnote{If you do not know how to open a terminal on Mac, then just type terminal in the spotlight (search tool on the top of the right corner) and once found just click on it.} and type

Note: Do not try to install scons using porticus or sudo port install scons, because if automatically installs another python version and you are likely run into problems with different python versions.

Install vtk-5.0.4 from source. If you install from ports it won't configure to use shared libraries. Once you untar it you will have (assume user is john)/Users/john/Downloads/VTK folder, then run following: